The present invention generally relates to optical switches, and more particularly to an assembly and a method for ensuring accurate alignment of optical fibers within an optical switch.
Conventional optical switches operate by displacing at least one of the fibers to contact the other fiber (closed position) or to release contact with the other fiber (opened position). Generally, die optical fibers connect one another at aids which are transverse to the longitudinal axis of the fibers and coplanar to one another. In the closed position, input light is transmitted from one optical fiber to the other with little or no transmission loss. In the opened position, input light is reflected from one of the fibers, leading to complete or partial transmission loss. Complete transmission loss occurs during total internal reflection, when light approaches a dielectric interface at or above a critical angle and is thereby inhibited from being transmitted to the other optical fiber. When the angle is below the critical angle, or the distance between the optical fibers is sufficiently small, some input light may cross the gap between the optical fibers and thereby frustrate the total internal reflection. An example of such a conventional optical switch is described in U.S. Pat. No. 5,390,266 (Heitmann et al.).
One disadvantage in conventional optical switches is obtaining an accurate fiber to fiber alignment. An accurate alignment between fibers assures low insertion loss. For example, a displacement done fiber relative to the other, either horizontally or vertically, of more than 1 micron will likely produce unacceptable insertion loss.
The invention provides an optical switch assembly that includes a fixed optical array, a movable optical array, a plurality of first optical fibers mounted on the fixed optical array and a plurality of second optical fibers mounted on the movable optical array, and a mounting apparatus. The fixed optical array is immobile relative to the mounting apparatus and the movable optical may is movable along the mounting apparatus.
The invention also provides a method for making an optical switch assembly. The method includes positioning a plurality of first optical fibers in a first support structure and a plurality of second optical fibers in a second support structure, mounting the first and second support structures on at least one mounting apparatus and affixing one of the first and second support structures to the mounting apparatus.
The foregoing and other advantages and features of the invention will be more readily understood from the following detailed description of the invention, which is provided in connection with the accompanying drawings.